Gauges

greencom · Post by **greencom** » Wed Jun 03, 2009 10:27 am

Hi everyone,
A question regarding the Douglas connectors on the dash gauges. There are two connectors on the back, one is larger in diameter than the other, what one goes to the sender ? My wiring has been removed from the dash and I cannot find any detailed wiring info for the gauges in any of my manuals for the early series M37.

Greencom

Paul in Kempner, TX · Wed Jun 03, 2009 11:26 am

TM 9-8030, 2 May 1955, page 258.

greencom · Post by **greencom** » Wed Jun 03, 2009 5:38 pm

Paul,
Thanks for the reply but that schematic only shows the lighting system of the truck, no gauges, no senders etc. I have yet to see a complete schematic in any of my manuals.

Greencom

52m37Hal · Post by **52m37Hal** » Wed Jun 03, 2009 7:09 pm

See the link below from Carl's site:

This shows the gauges. One of the gauge connectors is a male the other a female. If you look at the voltage gauge that only has one connector you can sort out what is what on the wiring diagram.

Hope this helps.
Hal

http://m37.crwdesigns.com/m37wiring.pdf

greencom · Post by **greencom** » Wed Jun 03, 2009 7:54 pm

Hi Hal,
I've seen this diagram, I believe it's for the later B1 M37. My "53 does not have a turn signal or voltmeter. I'm not sure if the gauges have the same left/right connections but if they do it will help some. I cannot believe there are no complete wiring diagrams to be found for the early generation of M37's. There is a low resolution picture of the instrument panel in my TM-8030 manual but it's almost useless. Thanks for your time Hal

Greencom

powerwagontim · Post by **powerwagontim** » Wed Jun 03, 2009 8:23 pm

Hi Greencom,
I posted a while back also looking for an early wiring diagram, both here and on Steel Soldiers. I had a couple of Guys say they had them but none ever materialized. Maybe your post will shake one free.
Tim

greencom · Post by **greencom** » Wed Jun 03, 2009 8:39 pm

HI Tim,
Yeah I hope one turns up. It's strange that the government omitted it in the original manuals. The books cover every tiny repair detail but I guess nobody ever had to repair instrument panel electrics or replace damaged wiring. It's something that I've noticed only recently when I decided to rip out all of the Bubba wiring in the panel and do it right except there is no way to find out how. I like to do things by the book but there is no book.
There is a definite difference in the wiring from the first and second generation of M37's.

Greencom

refit1701 · Post by **refit1701** » Thu Jun 04, 2009 3:45 am

You could try emailing or calling Joe Hall of Vintage Wiring of Maine. He builds harnesses for these trucks and will probably be able to answer your question. He's a great guy too.

greencom · Post by **greencom** » Thu Jun 04, 2009 7:01 am

refit1701 wrote:You could try emailing or calling Joe Hall of Vintage Wiring of Maine. He builds harnesses for these trucks and will probably be able to answer your question. He's a great guy too.

Thanks for the suggestion Refit. I would think he would know.

Greencom

DJ · Post by DJ » Thu Jun 04, 2009 6:04 pm

Check a M38 wiring diagram, all M series trucks use the same basic wire numbers . Would give you a starting point.

DJ

greencom · Post by **greencom** » Thu Jun 04, 2009 7:56 pm

Hi DJ,

That's right! The M38 has the same instrument panel. Thanks for that.

Greencom

greencom · Post by **greencom** » Thu Jun 04, 2009 8:36 pm

DJ,

I could not find any reference to what temp or oil gauge connectors go to the sender or the power. The wire numbers don't do me any good as I have no wires left, they've been removed. I'll just use mechanical gauges and be done with it. I guess the early fifties complete wiring diagram is a rarity.

Greencom

1953 M37

DJ · Post by DJ » Fri Jun 05, 2009 8:18 pm

I've got a complete wiring diagram for a M38. I tried to scan it so I could e-mail it ,but computers don't like old people. If you send me your address I would send them snail mail to you.

DJ

52m37Hal · Post by **52m37Hal** » Fri Jun 05, 2009 8:22 pm

Hey Greencom
Sorry the diagram did not help. I have a 52 and mine is the same as in the diagram. I have a volt meter and do not think I have seen an M37 without one. I have no turnsignal.

At any rate from the diagram you should be able to trace the power leads from the spider harness to the gauges you have. The other connection on the gauge goes to the sender.

I have a pic here somewhere of mine when I first opened it up and can e-mail it to you if you think it will help. Send me a PM and your e-mail address (52m37@charter.net).

I will take a look at mine this weekend and see if I can sort out if the larger connector is for the power or the sender.
Hal
'No battle plan survives first contact.'

greencom · Post by **greencom** » Fri Jun 05, 2009 8:55 pm

52M37Hal,

Actually Hal I was wrong, I do have a voltmeter, I don't know what made me think I had a n ammeter. Anyway after some bench testing I determined what connectors go where at the temp and oil gauges. They are however quite out of calibration according to the data I have. I would like to take you up on your offer to e-mail me a picture on your panel. I will pm you. Thanks for your efforts.
Greencom

Gauges

Gauges

Wiring Diagram